Photodynamic therapy (PDT) has developed rapidly in basic and clinical research, and its therapeutic prospects have received increasing attention. PDT has the advantages of minimally invasive, low toxicity, high selectivity, good reproducibility, protection of appearance and vital organ function, and has become a treatment. With the development of medicine, the field of application of PDT becomes more wildly, and brings a new direction for the treatment of oral diseases. This article reviews the basic principles, treatment elements and research results of PDT in the treatment of oral diseases.